To obtain additional information on the relation between charged groups on the cell surface and the immunological properties of the cell, a comparative electrophoretic and immunological study of human blood cells is proposed. Cells will be studied in the sequence 1) erythrocytes 2) normal lymphocytes 3) leukemic lymphocytes and lymphoblasts 4) granulocytes and 5) monocytes and macrophages both before and after treatment of the cell surface by neuraminidase, trypsin and other enzymes. The streak deflection method of Endless Belt Electrophoresis will be used both for measurement of mobilities and for preparative fractionation of cells for subsequent analysis or culture. Erythrocyte surface antigens will be determined by standard serological methods and determination of immunological reactivity against allogeneic or leukemic cells will be by mixed leukocyte culture methods. These studies should shed light on the relationship between surface charge, immunogenicity, malignancy, and on the role of enzymes, primarily neuraminidase in modifying the immune response to malignant cells. BIBLIOGRAPHIC REFERENCES: Luner, S.J., Sturgeon, P., McQuiston, D.T. and Szklarek, D.: Physico-chemical sialic acid content of erythrocytes from adult and umbilical cord blood. Pediat. Res. 9 583 (1975) Luner, S.J. and Szklarek, D. Electrophoretic Homogeneity of Human Erythrocytes: Studies of Old and Young Cells. Presented at 20th annual meeting of the Biophysical Society, Seattle; February, 1976. Biophys. J. 16 168a.